Extranodal lymphocyte predominance Hodgkin's disease. Clinical and pathologic features.

Although B-cell nodular lymphocyte predominance Hodgkin's disease (nodular paragranuloma, LPHD) typically presents at low stage, reported series have identified a minor population of patients with advanced disease. Clinicopathologic findings in 13 cases of LPHD are described that had extranodal manifestations. The B-cell immunophenotype was confirmed in all cases with paraffin-section immunostains. Nine patients presented with extranodal disease; distribution was in Waldeyer's ring (n = 2), spleen (n = 3), spleen and liver (n = 3), or bone marrow (n = 1). Three cases, clinically stage III/IV at presentation, had involvement of bone marrow (n = 2) or bone marrow, liver and spleen (n = 1) at relapse. One patient presented with clinical stage IIe disease and had involvement of spleen at relapse. Follow-up was available for 11 patients (range 4 months to 11 years; mean, 5 years). One patient died of disease and one died with disease because of therapeutic complications. Six patients were disease-free and three had persistent or recurrent LPHD. Microscopically, LPHD was difficult to recognize in extranodal sites and could easily be mistaken for low-grade non-Hodgkin's lymphoma or conventional Hodgkin's disease. Certain morphologic and immunophenotypic findings were effective in avoiding such diagnostic confusion. Thorough staging evaluation appears warranted for LPHD because it may be responsive to therapy, even in advanced stage or after relapse. Although LPHD is unexpected in extranodal samplings, the wary pathologist can suspect its presence on the basis of characteristic histopathologic features. Confirmation of the diagnosis may require paraffinsection immunostains.